A closure of this kind was disclosed, for example, in German patent specification No. 3,031,945. This closure from the same inventor has the following disadvantages:
(a) The canisters do not stack well because the second canister stacked on a particular canister is poorly supported in the region of the closure. PA1 (b) The closure is made up of a large number of different parts. PA1 (c) It is difficult to open if an attendant is wearing gloves. PA1 (d) In practice, a safety catch prestressed by a leaf spring is necessary to ensure that the closure does not come open under adverse conditions. It is thus necessary, first of all, to undo the catch and then open the claw. If, however, in disaster situations, several hundred canisters have to be opened quickly, this means an extremely great loss of time and furthermore, that an attendant will be able to open perhaps 30 canisters but will then be lacking the strength to open further canisters. PA1 (e) The force required to open and close the claw is great, even disregarding the leaf spring catch. PA1 (f) In a drop test, a full canister is thrown closure-first from a height of several meters onto a concrete slab, both when the temperature is extremely low and when it is extremely high. In the case of the known closure, it is difficult to fulfill these conditions. PA1 (g) Although the overall design of the closure makes it possible to cast the collar in metal, it is not possible in the case of this design to produce the claw and the cap by casting as well, whether in plastic or optionally metal and/or plastic. PA1 a collar coaxial with a pouring spout on the canister, having a rearward periphery and sides having two abutments, the abutments having lower surfaces arranged to cooperate with the claws of the closure, PA1 a cap with a sealing ring therein and lateral and rearward edge regions, the cap being arranged to swing between an open condition and a closed condition relative to the collar, PA1 a first hinge half projecting from the rearward periphery of the collar, PA1 a second hinge half on the rearward edge region of the cap that cooperates with the first hinge half, PA1 the first and second hinge halves being shaped to prevent the cap from swinging to the closed condition when the cap is in the open condition, PA1 two journals arranged on the lateral edge regions of the cap, and PA1 a claw that is approximately U-shaped, seen in plan view, with a transverse gripping web with end regions, and two longitudinal webs emanating from the end regions, PA1 each of the longitudinal webs ending at a free end in a fork having an upper and a lower prong as seen in the closed condition of the cap, PA1 each of the upper prongs being arranged to form a swivel hinge with the journals, PA1 each of the lower prongs having an inner surface arranged to cooperate with the lower surfaces of the abutments such that when the gripping web is pressed downward the sealing ring in the cap is pressed onto the end face of the pouring nozzle, PA1 the collar being arranged to fit against the cap with minimal spacings and the claw being arranged to fit against the collar and the cap with minimal spacings, when the cap is in the closed condition, the spacings permitting relative movement of the claw and the cap during opening and closing of the cap, the spacings being smaller than deformations occurring as a result of impact loads on the closure.